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High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two DeltaI=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by DeltaI=1 and DeltaI=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and establishes the primarily geometric nature of this phenomenon.

A particle plus triaxial rotor model was applied to odd‐odd nuclei in the A ∼ 130 region in order to study the unique parity πh11/2⊗νh11/2 rotational bands. With maximum triaxiality assumed and the intermediate axis chosen as the quantization axis for the model calculations, the two lowest energy eigenstates of a given spin have chiral properties. The independence of the quantity S(I) on spin can be used as a new criterion for chirality. In addition, a diminishing staggering amplitude of S(I) with increasing spin implies triaxiality in neighboring odd‐A nuclei. Chiral quartet bases were constructed specifically to examine electromagnetic properties for chiral structures. A set of selection rules unique to chirality was derived. Doublet bands built on the πg9/2⊗νh11/2 configuration have been discovered in odd‐odd 104Rh using the 96Zr(11B, 3n) reaction. Based on the discussed criteria for chirality, it is concluded that the doublet bands observed in 104Rh exhibit characteristic chiral properties suggesting a new region of chirality around A ∼110. In addition, magnetic moment measurements have been performed to test the πh11/2⊗νh11/2 configuration in 128Cs and the πg9/2⊗νh11/2 configuration in 104Rh.

The mass A = 130 region has been of particular interest both theoretically and experimentally as nuclei in this region are expected to exhibit soft behaviour related to the shape asymmetry parameter γ. The level scheme has been extended considerably up to spin 83/2− with a further possible transition to spin 85/2−.

High-spin states have been studied in neutron-deficient {sup 124}{sub 57}La{sub 67}, populated through the {sup 64}Zn({sup 64}Zn,3pn) reaction at 260 MeV. The Gammasphere {gamma}-ray spectrometer has been used in conjunction with the Microball charged-particle detector, the Neutron Shell, and the Argonne Fragment Mass Analyzer, in order to select evaporation residues of interest. The known band structures have been extended and new bands found. Most of the bands are linked together, allowing more consistent spin and parity assignments. Comparison of band properties to cranking calculations has allowed configuration assignments to be made and includes the first identification of the g{sub 9/2} proton-hole in an odd-odd lanthanum isotope. Two bands have been assigned a {pi}h{sub 11/2}{circle_times}{nu}h{sub 11/2} structure; the yrast one exhibits a signature inversion in its level energies below I=18.5{Dirac_h}, while the excited one exhibits a signature inversion above I=18.5{Dirac_h}.

High-spin states have been studied in neutron-deficient Xe-114(54), populated through the Ni-58(Ni-58,2p) fusion-evaporation reaction at 230 MeV. The Gammasphere gamma-ray spectrometer has been used in conjunction with the Microball charged-particle detector in order to select evaporation residues of interest. The yrast band has been greatly extended to a tentative spin of 52 (h) over bar and shows features consistent with smooth band termination. This band represents the first evidence for a core-excited (six-particle, two-hole) proton configuration above Z = 53.

Nearly degenerate partner bands observed in $A\ensuremath{\sim}130$ odd-odd triaxial nuclei are interpreted as a manifestation of chirality in the intrinsic reference frame. A phenomenological approach, based on a core-particle-hole coupling model, has been developed to address the experimental observables. This laboratory-frame model, in which chiral symmetry has been restored, includes a triaxial core, a particle/hole single-particle Hamiltonian, and quadrupole-quadrupole interactions. The optimal model parameters are investigated. The results of the calculations indicate the existence of pairs of $\ensuremath{\pi}{h}_{11/2}{\ensuremath{\nu}}^{\ensuremath{-}1}{h}_{11/2}$ states with the same spin, parity, and similar excitation energy forming partner bands that are nearly degenerate over a range of spins. These calculated partner bands are consistent with the chiral band interpretation and are in agreement with experimental observations in this region. This model has been applied to excited states in ${}^{132}\mathrm{La},$ which have been studied via the ${}^{123}\mathrm{Sb}{(}^{13}\mathrm{C},4n)$ reaction using \ensuremath{\gamma}-ray spectroscopic techniques. In addition to the yrast $\ensuremath{\pi}{h}_{11/2}{\ensuremath{\nu}}^{\ensuremath{-}1}{h}_{11/2}$ band, the partner band was observed with experimental properties consistent with the same $\ensuremath{\pi}{h}_{11/2}{\ensuremath{\nu}}^{\ensuremath{-}1}{h}_{11/2}$ configuration. These doublet bands resemble those observed systematically for several $N=75$ isotones of ${}^{132}\mathrm{La}.$

Chirality in triaxial odd-odd nuclei is discussed as a novel form of spontaneous symmetry breaking in nuclear structure physics. It is shown that the orthogonal coupling of angular momenta for the valence proton, valence neutron and the core rotation, which violates time reversal, results, for specific configurations, from the triaxial shape and irrotational flow moment of inertia. The model calculations are investigated as a study of the characteristics of chirality. Recent progress from experimental studies of the πh11/2νh11/2 partner bands in triaxial A∼130 nuclei is reviewed.Chirality in triaxial odd-odd nuclei is discussed as a novel form of spontaneous symmetry breaking in nuclear structure physics. It is shown that the orthogonal coupling of angular momenta for the valence proton, valence neutron and the core rotation, which violates time reversal, results, for specific configurations, from the triaxial shape and irrotational flow moment of inertia. The model calculations are investigated as a study of the characteristics of chirality. Recent progress from experimental studies of the πh11/2νh11/2 partner bands in triaxial A∼130 nuclei is reviewed.

The Kerman-Klein-Donau-Frauendorf (KKDF) model is a linearized version of the Kerman-Klein (equations of motion) formulation of the nuclear many-body problem. In practice, it is a generalization of the standard core-particle coupling model that, like the latter, provides a description of the spectroscopy of odd nuclei in terms of the properties of neighboring even nuclei and of single-particle properties, that are the input parameters of the model. A divers sample of recent applications attest to the usefulness of the model. In this paper, we first present a concise general review of the fundamental equations and properties of the KKDF model. We then derive a corresponding formalism for odd-odd nuclei that relates their properties to those of four neighboring even nuclei, all of which enter if one is to include both multipole and pairing forces. We treat these equations in two ways. In the first we make essential use of the solutions of the neighboring odd nucleus problem, as obtained by the KKDF method. In the second, we relate the properties of the odd-odd nuclei directly to those of the even nuclei. For both choices, we derive equations of motion, normalization conditions, and an expression for transition amplitudes. We also solve the problem of choosing the subspace of physical solutions that arises in an equations of motion approach that includes pairing interactions., Comment: 27 pages, Latex

Excited states in ${}^{126}\mathrm{Ce}$ have been observed with the GAMMASPHERE \ensuremath{\gamma}-ray detector array, used in conjunction with the MICROBALL charged-particle detector. The reaction ${}^{64}\mathrm{Zn}{(}^{64}\mathrm{Zn},\mathrm{xpn}\ensuremath{\alpha})$ (beam energy 260 MeV) was used to populate a wide range of nuclei in the neutron-deficient region with $A\ensuremath{\approx}120.$ ${}^{126}\mathrm{Ce}$ was populated via the $2p$ evaporation channel. The three previously observed bands have been extended to higher spins and some other structures have been identified. The yrast band shows evidence of a delayed neutron alignment occurring at a rotational frequency \ensuremath{\omega}\ensuremath{\approx}0.5 MeV/\ensuremath{\Elzxh} as observed in the neighboring odd-A nucleus ${}^{127}\mathrm{Pr}.$ One of the two excited bands shows evidence for a similar crossing at a slightly lower frequency and also exhibits a sudden gain in alignment at \ensuremath{\omega}=0.57 MeV/\ensuremath{\Elzxh}. The third band may involve the coupling of a \ensuremath{\gamma}-vibrational state. All three rotational bands are discussed in terms of standard and extended cranked shell model calculations.

The decay of the ${K}^{\ensuremath{\pi}}{=8}^{\ensuremath{-}}$ isomer in ${}^{132}\mathrm{Ce}$ with an excitation energy of 2340.2 keV has been investigated using the ${}^{120}\mathrm{Sn}{(}^{16}\mathrm{O}{,4n)}^{132}\mathrm{Ce}$ reaction. A half-life of 9.4\ifmmode\pm\else\textpm\fi{}0.3 ms was determined. Two new decay paths have been found in the deexcitation of this isomer. The hindrance factors for the $E1,$ $M2,$ and $E3$ transitions deexciting the isomer have been determined. The decay properties of the ${8}^{\ensuremath{-}}$ isomers in the $N=74$ isotones are discussed. A band mixing mechanism involving the ground state and $s$ band seems to be responsible for the behavior of the reduced hindrance factors of the $E1$ transitions deexciting the ${K}^{\ensuremath{\pi}}{=8}^{\ensuremath{-}}$ isomers in these isotones. A $K$ mixing, characteristic of the axially asymmetric nuclei, may account for the reduced hindrance factors of the $E3$ transitions to the ${5}_{\ensuremath{\gamma}}^{+}$ states in ${}^{130}\mathrm{Ba}$ and ${}^{132}\mathrm{Ce}.$

New sideband partners of the yrast bands built on the pi(h11/2)nu(h11/2) configuration were identified in 55Cs, 57La, and 61Pm N = 75 isotones of 134Pr. These bands form with 134Pr unique doublet-band systematics suggesting a common basis. Aplanar solutions of 3D tilted axis cranking calculations for triaxial shapes define left- and right-handed chiral systems out of the three angular momenta provided by the valence particles and the core rotation, which leads to spontaneous chiral symmetry breaking and the doublet bands. Small energy differences between the doublet bands suggest collective chiral vibrations.

High-spin states in the near proton-dripline nucleus {sup 107}Sb have been identified, and collectivity in this nucleus has been observed for the first time in the form of two rotational bands. One of the observed rotational structures is a {delta}I=1 band, and is interpreted as based on a {pi}(g{sub 9/2}){sup -1}(multiply-in-circle sign){pi}(g{sub 7/2}d{sub 5/2}){sup 2} proton configuration. A second structure has {delta}I=2 character, and is explained as being based on a {pi}h{sub 11/2}(multiply-in-circle sign)[{pi}(g{sub 9/2}){sup -2}(multiply-in-circle sign){pi}(g{sub 7/2}d{sub 5/2}){sup 2}] proton configuration through comparison with cranked Nilsson-Strutinsky model calculations. The calculations predict that this band terminates at a spin of 79/2 ({Dirac_h}/2{pi}). (c) 2000 The American Physical Society.

A level scheme is presented for ${}_{53}^{111}\mathrm{I},$ populated by the ${}^{58}\mathrm{Ni}{(}^{58}\mathrm{Ni},\ensuremath{\alpha}p)$ reaction. A backed-target experiment, at a low beam energy of 210 MeV, was performed using the JUROSPHERE spectrometer, while a thin-target experiment at 250 MeV was performed using the GAMMASPHERE spectrometer in conjunction with the MICROBALL charged-particle detector array. The new level scheme fits well the systematics of light iodine nuclei and provides evidence for a terminating band at the highest spins. Low-lying transitions previously assigned to ${}^{111}\mathrm{I}$ could not be confirmed.

Free access to scientific resources and the role of libraries In the field of scientific publishing, the movement for open archives has led to changes which the author of the article analyses from four points of view. The first highlights the relationship between libraries and publishing and its destabilisation due to digitization. A more historical approach identifies the contribution of three parallel movements: the development of the web, the saturation of the publishing industry and international scientific politics. An approach per discipline gives an overview of ongoing evolution. Finally an economic approach puts the accent on added value from the various players, its remuneration and the limits of the consideration afforded to available documents.

Three long, strongly coupled (ΔI=1) sequences have been identified in 110,112Te by using the GAMMASPHERE array in conjunction with the MICROBALL charged-particle array. These bands are interpreted in terms of deformed proton 1-particle–1-hole bands that reach termination at I∼40ℏ. This is the first observation of such collective dipole structures in this mass region. In contrast, many shorter dipole sequences have been associated with weakly deformed structures that generate angular momentum by the shears mechanism (magnetic rotation).

Lifetime measurements of states in the yrast band of 119Xe have been performed using a Doppler broadened lineshape analysis. Preliminary results, in the range 27/2−⩽Iπ⩽43/2−, indicate a transition quadrupole moment of approximately 2.9 eb, which corresponds to a prolate rotor with deformation e2≈0.17.

The properties of exotic neutron-rich nuclei between the proton shell closures Z = 20 and Z = 28 are of particular interest for the understanding of the shell structure for large neutron excess. Effects related to the energy gap between the neutron fp and 1g9/2 shells lead to a strong variation of collectivity for nuclei around N = 40. Whereas 68Ni was found to have doubly magic properties, this was not observed in neighbouring nuclei. Recent shell model calculations for the neutron rich iron isotopes clearly reveal the difficulty to describe nuclei in this mass region and resulted in large deviations of the predicted collectivity depending on the valence space. However, no experimental data on the transition strength existed for the very exotic nucleus 66Fe at N = 40. Here we present the newest results on absolute transition strengths of the lowest excited states in 62,64,66Fe measured model independently using the recoil distance Doppler-shift (RDDS) method. The experiments were performed at NSCL at Michigan State University with the Cologne/NSCL plunger device using Coulomb excitation in inverse kinematics at energies of 80 MeV/u. Our results yield a much higher collectivity for 64,66Fe than expected and allow tests of new calculations.

Absolute transition probabilities are fundamental observables for nuclear structure. The recoil-distance-Doppler-shift (RDDS) technique, also called plunger technique, is a well established tool for the determination of these important experimental quantities via the measurement of lifetimes of excited nuclear states. Nowadays nuclear structure investigations are concentrated on exotic nuclei which are often produced with extremely small cross sections or with very low beam intensities. In order to use the RDDS technique also for the investigation of very exotic nuclei this method has to be adapted to the specific needs of these special reactions. This article gives an overview on recent RDDS measurements with the new differential plunger in combination with particle detectors and recoil spectrometers. These were done with projectile multistep Coulomb excitation at low beam energies (≈ 5 MeV/u) and at intermediate beam energies (≈ 100 MeV/u) using one step Coulomb excitations and knockout reactions.

Chiral partner candidate bands have been found in $^{103}\mathrm{Rh}$. As a result of this observation, a special quartet of neighboring chiral candidate nuclei can be investigated for the first time. With this quartet identified, a comparison between the behavior of the nearly degenerate doublet bands belonging to the same core but to different valence quasiparticle configurations, as well as belonging to different cores but to the same valence quasiparticle configuration, becomes possible. The comparison shows that the energy separation of these doublet band structures depends mainly on the core properties and to a lesser extent on the valence quasiparticle coupling. This observation sets up new criteria for the explanations of the band doublings, restricting the possible scenarios and providing new information on the characteristics of the underlying mechanism; it is in qualitative agreement with the chiral scenario.

Gallium phosphide films were grown by r.f. sputtering on glass slides and on glass slides coated with thin gold films. The growth temperature ranged from the ambient to 540°C. With increasing growth temperature the film structure changed from amorphous to polycrystalline on the glass substrates and from amorphous to strong [100]-textured polycrystalline on the gold film substrates. The temperature of the amorphous-to-crystalline transition was slightly above 200°C for a deposition rate of 45 nm min -1 . The electrical properties were strongly dependent on the growth temperature. The temperature dependences of both the resistivity and the relaxation time were fitted by the relation exp {(T 0 /T) 1 4 } and a heterogeneous model is proposed.

High-spin states in 105 Rh were populated by the 96 Zr( 13 C, p3n) reaction at beam energies of 51 and 58 MeV, and studied using the EUROBALL IV γ -ray spectrometer and the DIAMANT charged particle array. A pair of nearly degenerate Δ I = 1 three-quasiparticle bands with the same spins and parity have been observed. Comparison of the experimental results with tilted axis cranking calculations confirms the chiral character of the two bands, while arguments based on the excitation of particles within the π g 9 / 2 ν ( h 11 / 2 ) 2 configuration of the yrast band and comparison with the previously observed γ band exclude the other possible interpretations. This is the first experimental evidence for three-quasiparticle chiral structure in the A ∼ 100 region, and the first simultaneous observation of a γ band and chiral partner bands in one nucleus.

The GRIFFIN (Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei) project is a major upgrade of the decay spectroscopy capabilities at TRIUMF-ISAC. GRIFFIN will replace the 8π spectrometer with an array of up to 16 large-volume HPGe clover detectors and use a state-of-the-art digital data acquisition system. The existing ancillary detector systems that had been developed for 8π, such as the SCEPTAR array for β-tagging, PACES for high-resolution internal conversion electron spectroscopy, and the DANTE array of LaBr3/BaF2 scintillators for fast γ-ray timing, will be used with GRIFFIN. GRIFFIN can also accommodate the new neutron detector array DESCANT (Deuterated Scintillator Array for Neutron Tagging), enabling the study of β-delayed neutron emitters. DESCANT consists of up to 70 detectors, each filled with approximately 2 liters of deuterated benzene, a liquid scintillator that provides pulse-shape discrimination (PSD) capabilities to distinguish between neutrons and γ-rays interacting with the detector. In addition, the anisotropic nature of n-d scattering as compared to the isotropic n-p scattering allows for the determination of the neutron energy spectrum directly from the pulse-height spectrum, complementing the time-of-flight (TOF) information. The installation of GRIFFIN is under way and first experiments are planned for the fall of 2014. The array will be completed in 2015 with the full complement of 16 clovers. DESCANT will be tested coupled with GRIFFIN in spring of 2015.

International audience; 136 P. Joshi et al. / Physics Letters B 595 (2004) 135–142AbstractThe nucleus 106Rh was populated using the reaction 96Zr(13C, p2n) at a beam energy of 51 MeV. γ -ray transitions wereidentified using the EUROBALL-IV γ -ray spectrometer and the DIAMANT charged particle array. The yrast band, which isbased upon a πg−19/2 ⊗ νh11/2 configuration, has been extended to I π = (22−). A new I = 1 band has been identified whichresides ∼ 300 keV above the yrast band. Core–quasiparticle coupling model calculations show reasonably good agreement withthe data. The properties of the two pairs of strongly coupled bands are consistent with a chiral interpretation for these states. 2004 Elsevier B.V

Description de la preparation de couches minces de Al x In 1-x N pour pulverisation reactive par cible multiple. Les resultats des etudes en spectroscopie Auger, combinees avec ceux d'autres methodes, montrent que ces films sont homogenes et forment des solutions solides dans tout le domaine de composition

The systematics of smoothly terminating rotational bands based on proton 2p-2h excitations in the A=110 mass region are presented. Terminating bands (or nearly so) based on this proton excitation have been found in nuclei ranging from 107In, up to 114Te, and possibly extending to 54Xe nuclei. The impressive agreement between experimental data and theoretical calculations is also presented. However, recently discovered structures based on proton 1p–1h excitations begin to show disagreement with theoretical calculations. These new bands are also discussed. The current and future directions of research into smooth band termination will be presented.

Odd-odd nuclei treated as core-particle-hole systems with various collective cores and various particle-hole configurations are investigated within the Core-Particle-Hole Coupling (CPHC) model. A new symmetry, called the S-symmetry, is identified as a combination of the α-parity of the collective core and the proton-neutron symmetry of the valence proton and neutron in particle-hole configurations involving single-particle states with the same quantum numbers. It is found that the S-symmetric odd-odd nuclei show signatures which are usually considered as fingerprints of nuclear chirality, namely doublet band structure with a particular pattern of electromagnetic transitions. Reported results imply that the rigid rotor with a symmetric valence proton-neutron configuration is only a special case of the system with the novel S-symmetry. Therefore, it is an open question whether the chiral fingerprints discussed so far identify uniquely the orthogonal coupling of angular momentum in the intrinsic system.